<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        .outer1 {
            height: 400px;
            background-color: #ccc;
            position: relative;

        }

        .inner1 {
            background-color: orange;
            font-size: 20px;
            padding: 20px;
            border: 20px solid #000;
            position: absolute;
            left: 0;
            right: 0;
            top: 0;
            bottom: 0;
            margin: 20px;
        }

        .outer2 {
            width: 800px;
            height: 400px;
            background-color: #e45f5f;
            position: relative;
        }

        .inner2 {
            width: 400px;
            height: 100px;
            background-color: #51b561;
            font-size: 30px;
            position: absolute;
            left: 0;
            top: 0;
            bottom: 0;
            right: 0;
            margin: auto;
        }
    </style>
</head>

<body>
    <div class="outer1">
        <div class="inner1">
            特殊应用
        </div>
    </div>
    <div class="outer2">
        <div class="inner2">inner2</div>
    </div>
</body>

</html>